Pneumatic hammer.



' 1 July 4,1911.

2 SHEETS-SHEET l S. GLDHAM. PNEUMATIG HAMMER. 1 APPLICATION FILED JMMQ, 1911.

@Y f WN f. .mm Q .wah Ww lwv INVENTQP 'LQ/W SWQW ...1. n@ www D S. OLDHAM.

PNEUMATIG HAMMER.

APPLIOATION FILED JANJQ, 1911.

` 996,880. A Patented July 4,1913

2 SHEETS-SHEET 2.

wn ss' ATTUREEYS f nioivrrED. sTATEsg-PATENT oEEioE.

-. #seamen :13am, or PHILADELPHIA, rENNsYLvANu, ASSIGNOBL To GEORGE oLDHm & soN COMPANY, A'coRroaATIoN or PENNSYLVANLL To all tuhom "it may concern:

Be it known that I, SAMuEn OLnHAM,

a 'citizen of the United States, residing 'in the city and county of Philadelphia, State of Pennsylvania, have invented a new and useful Pneumatic Hammer, of which the lfollowing is a specification.

My present invention relates to that class of fluid actuated tools commonly known as pneumatic hammerswherein the blow of a reciprocating piston is imparted to the working tool, such piston being controlled by a valve mechanism located in proximity to-one end of the piston cylinder, the valve of said mechanism being cup shaped, and imperforate and being moved in its forward 'direction Aby live air, and in its rearward V'direction by the momentum of the piston `fand for .purposes of illustration, I have shown a construction in which the length of Astroke of the iston isvgreater than its own length, it being apparent to those skilled in this art'th'at the novel valve mechanism herein disclosed is equally adaptable for a -`construction wherein the lengtho stroke "of the piston is less than the length of the 'piston.

My invention consists of a novel construction of 'iiuid actuated hammer having a sot shaped valve and a novel valve movement,

novel construction of an imperforate, cup

the' valve mechanism being located at one end of the piston cylinder and preferably in alinement therewith. l

It further consists of a novel manner of changing the valve which is moved in one direction by live motive Huid and in the opreciprocating piston. 40'

positedirection by the momentum of the It fui' her consists of novel meansl for causing the initial forward movement of the reciprocatlng piston.

It further consists of a novel construc- 1 tion of animperforate.valve into which the piston'ijs adapted to travel, said valve having'jan open end and imperforate walls and provided on its inner periphery with a groove for conducting live motive fluid 'along the piston to the rear end thereof.

j It further consists of other. novel features of construction, all as will 'be hereinafter fully set forth. y i

Specification of Letters Patenti Application tiled' January 19, 1911.

va cylindrical bolt of uniform PNEUMATIC HAMMER.

Patented July 4, 1911. serial No. 603,458.

For the purpose of illustrating 'my invention, drawin one form thereof which is at present pre erred by me, since the same has been found in practice. to give satisfactory and reliable results, although it is to be understood that the various instrumentalities of which -my invention consists can be vari- I have shown in the accompanying ously arrangedand' organized and that my invention is not limited to the precise arrangement and organization of these instrumentalities as herein shownand described.-

Figure l represents a longitudinal section of a pneumatic hammer .embodying my invention. section of showing the partsin the position they assume at a differentstage oi the operation. Fig. 3 represents a perspective view vof the Fig. 2 represents aJOngitudinal valve. Fig. Ltrepresents a longitudinal section of the valve. Fig. 5 represents, on an enlarged scale, a longitudinal sectional view of the "remmer, with the parts in the position seei... in Fig. 1.

Similar numerals of reference indicate corresponding parts in the figures. Referring to the drawings, 1- designates the cylinder 1caving the shank 2 of the rivet set or etl :er working tool 3 inserted therein and provided with the piston 4.

5 designates thevalve block having the valve 6 therein and 7 ing handle of the tool having the threaded sleeve 8 v'in engagement With the cylinder l,

'whereby the handle, valve block and cylmy device similar to Fig. l but' yso designates the grasp-v grasping part of the the valve' Gis. cup-shaped having one end open and the other end closed by a wall l1 of considerable thickness and terminating in the head or flange 12. .I -13 designates a fiange or rib o'less diameter and width than the head l2, being 2 I ecosse separated from the latter by the groove 15, while thehead 14 is of greater width than the head 13 and islseparated therefrom by the groove 1G. f

-5 1? designates a preferably spiral groove in the inner wall. 18 of the valve G, said groove begim'iing at the vpoint 19 and ter,- niiiiating at the point 20.-

lVhen the parts are in the position iiidicated in Fig. 1, the throttle lvalve 10 is closed and the valve 6 and piston 4 are in their extreme foi-Ward position. On moving the throttle valvelO to the position indicated in Fig. 2, the live air, when the parts are in the position Seen in Fig. l, passes' into the pas* "I, sages 21 and 22 and the port 23 by the groove lGvand port 2/1 into the passage 25 .of the valve block 5 into the passage `2G and through the port 27 into' the chamber 2S and the piston starts on rearward stroke or toward the valve 6. The exhaust from the rear of the piston passes through the port 29, passage 30 and port 31 around groove 15 and out ports 32 and 33 to the atmosphere,

the valve. still being in the position seen in Fig. l. The valv'e ti remains in the position seen in Fig. 1 until the. piston L1 moves past t-lie port 29 toward the position seen in Fig. 2,A whereupon the valve is moved rearwardly slightly to the. left of the position seen in said F ig. 2 bythe momentum .of the piston 4 which is governed by the location of the port 29. The air In rear of the valve G escapes to the atmosphere through port 35 passage 35, ports 3G and 3T, piston chamber 38,.port 2T, passage 2G, passage 25, port X11, around annular groove 15, ports 32, and

ports I desire at. this point to call especial atf1() tention to the fact that my novel const ruction of iniperforate, cup-shaped valve is shifted rearwardly oi' toward the handle by the momentum rif-thc piston for the following reasons. l locate the port 2.) at the mouth or open end of the valve so thatwhen the pistou moves rearwardly pastsaidpoi'tf, it willt'rap a `body of air within the imperforato cup shaped valve', and will compress said body of air to such an extent that an air butler is formed within the valvel The valve and piston now move rearwardly in unison by reason of the momentum of the piston to the full extent. of the length of stroke o' the valve. Dill-ing this continued rearward .stroke of the valve alid piston, owing to the momentum offthe piston. the piston continues itsi'earwari'l movement after tlie'rimrward movement ofythefvalve has ceased. whereby this trapped body of air,

becomes compressed'to'agfrcater extent, .soas to accelerate the. initial forward movement. of thc piston. f

lt. will he apparent; that hy ...eating the' )ort 'Yi'toward `the forward end of. the cy'l'i-nfA der, the air .troni the rear of the valve G is permitted to exhaustearlier, whereby re' sistance to the rearward movement of the ivalve, effected by the momentuntcf the piston, as above explained, is reduced to a minimum. f 70 `I am aware that it is a common right to move a` fluid actuated 'valve in a pneumatic 'impact tool by compression of air between.

the valve and the piston, as in British patent to Lake, No. 2182, of i875, in patentto Von '15 Buhler, No. 510,155, Dec. 15, 1893; and Uren, No. 303,344, Aug. 12, 1884:, but Ido not desire'to employ s uch construction as I- have found my method of valvular operation to be more reliable in practice. and, tov 8O produce more satisfactory results. Iii the prior art 'devices when the valvegets worn or tits loosely in its valve box, it will be apparent that liveair can, or is liable, to leak into the `compression chamber which will S5.

cause the v-alve to change earlier than. it should and the tool will then C short stroke or in other words, the piston will not travel its full length on its rearward trolte, an objectionable feature, which is `entirely ob-v-ill' viated in my novel tool. Returning now-to the detailed operation-` of my novel valve mechanism, it will be seen that the piston 4 and the valve 6 have now assumed the posif" tion seenin Fig. 2,whereuponlive.-m0tive,95. fluid may pass through the port- 23, thence through the groove or passagel? in rear of the piston to causethe initial forward move-v ment of the piston 4.

lt will be under stood,by those skilled in .i100v the artl that in the ordinary or normal operation of the tool, the piston 1v instantly shifts. or reverses its movement, as above explained, and that the especial function of the groove i '17 to admit live air instantly to the rear 105 of the piston, in case the piston vshould happen to be in its extreme rear position :when the air is turned` on, which vmight oceurj' when the tool is held in'a. verticalor npr? wardly inclined position before the mot-ivd fluid is admitted to it. As soon as'tli'e pistoh passes the portl 23. itI will receive. the full force of the live motive fluid. -Tlie airiin/ front of the piston may exhaust throughl port 27, passage 26, passage 25, also port' 115 4l., .around groove 1.5i, and Athence through ports 32 and 33 to theatmosphele. As soon as the pistone mcovers the port 36, live motive fluid may pas's through plissage 35 and port 311 in rear o the valve Scand cause the latter to be initially moved forwardly,

i'tbeing clear that after the piston has passed port. 37 liv'e motive fluid mayipass through both-the ports 36 and-37 -nto passa-ge 35'and thence throngh. port 34 in rearof the Valve 1'25 land 'maintain'ftfhe same in its forward posi tion, the valve remaining in such forward position until 1tis moved rearwardly vby the momentum of the piston. #t0 is a clamping ring, preventing im- 130' roper movement of the handle and cylinenf The valve 6 at'its rear end is preferably of a considerable thickness in order to impart weight thereto, the result of which is li that the valve moves forwardly and more readily when the cylinder is heldin such a manner that the working ltool is pointing downwardly. The groove 17 on the inner face ofthe valve may extend in vany desired La direction from the open end of the valve to the rear wall or end thereofl Special attention is directed to the novel construction of valve mechanism employed and, its novel manner of operation, especial mattention being called to the fact that the valve is operated in its rearward direction by Y the momentum of the piston and is thus differentiated from the rior structures al- 'ready referred to Valso fiom prior devices, 'isuch as Meissner, No. 822,146, patented May 29, 1906, wherein the valve is shifted by `compression of the air between it and the piston 'atthe 'return stroke of the latter'` ',Attentionis also directed to the novel con- Zlistruction 'of valve which is provided with -imperforate walls andan imperforat'e end .and the internal groove 1 7 which may bestraight or 'spiral or of such contour as to 'conduct live motive, li'uid 4to the rear of the valve to-effect the initial forward movement' of the piston, when the parts are in the 'positionseen in Fig. 2. By the employment of ijihaving -a port for the fluid control of said i .'valve opening into the cylinder at a greater i distance from either end of the cylinder `than the length of the piston, I ainenabled tovprovide a 'novel `valve mechanism which :'sliifts instantly ,inY the desired direction 'and .epablesmy piston to strike a very powerful and heavy blow directly upon the shank of the button set, rivet set, chisel or other workintool.

y theoo-aetion between the parts corn- 5.5 pris'lng the pneumatic hammer proper, such 4as the cylinder, a piston therein construct.

ed asdescribed and having av length of stroke greater than its own length, the novel et-Qfvalve mechanism located wholly at one end ofi the cylinder and. consisting of a cup shaped," imperforate valve, shifted bythe momentum of the piston, said valve having grooves thereon as described, which is held to have theI 1nposition by thesgrasping handle and itsA ling the efhaust and adjuncts, taken in conjunction with the supply duct and the throttle valve located wholly outside of the grasping portion of said handle, I am enabled to provide a tool of great simplicity and durability at a minimum cost. It will be understood that while the present invention is applicable for riveting and other work in metal as chipping, calking and the like, I do not desire to be limited thereto, since my invention is applicable for all uses wherein a mallet and chisel have heretofore ordinarily been employed.

It will now be apparent that I have'de vised a novel and useful construction of a pneumatic hammer which embodies the features of advantage enumerated as desirable in the statement of the invention and the above description and while I have, in the present instance, shown and described a preferred embodiment thereof which has been found in practice to give satisfactory and reliable results, the same is susceptible of modification in various particulars without departingfrom the spirit or scope of the invention or sacrificing any of its advantages.

Having thusdescribed my invention, what- I claim as new and desire to secure by Letters Patent, is: i

l. In an impact tool, a rocating piston therein, sha ed valve arranged in alinement with said) piston and adapted to have the latter enter and cushion in it, means for shifting said valve forwardly by live air'- pressure,

and means for enabling said valve to be shifted rearwardly by the momentum of said'.

piston.

2. In animpact tool, a cylinder, a reciprocating piston therein, inlet and exhaust passages for the-motive Huid, an imper'forate cup yshaped val-ve'movable in a chamber at the rear end of the cylinder and vadapted to have the piston enter and cushion Within it, and means for enabling said valve to be shifted forwardly by live air and rearwardly by the' momentum of the piston.

cylinder, a recip-V an imperforate cup.

it is to be understood that 3. In an impact tool, a cylinder,.a reciprocating piston therein, an imperforate cupl shaped valve, located at the rear of said piston and in alinement therewith and adapted d ltteil'enter, vand cushion within it, sai cy 1n er aving ports 'and assas for causinig said valve .to be shifed fwardly by-live air pressure, and means for. enabling sa'l valve to be shifted rearwardly by the momentum of said piston.

4. In an impact tool, a cylindena recip rocating piston therein,l an imperforate cup shaped valvb arranged in alinement with said piston and adapted' to have" the latter- I,

enter and cushion in it and having a' plurality of grooves thereon,

one groove control-4 the other of Asaidgrooves controlling' the inlet of motive fluid, means for shifting said valve forwardly by live motive fiuid,`and means for-enabling said valve to be shifted rearwardly by thev 5 momentum of the'piston as the latter approaches the extremity of its rearward stroke. 5 As an improved varticle of manufacture, a hollow valve having a groove on its l0 inner periphery, extending from the open end ofsaid valv'e to its rear end and adapted to admit'motive fluid to the rear of the interior of said valve to effect the initial movement of the piston;v y y' 6, As an improved article of manufac I ture, a hollow cup shaped valve having a groove on its inner periphery, extending from the open end of said' valve to its .rear end and adapted to admit 4motive'luid to ,the rear of said valve to effect the initial movement of the piston.

7; As an improved article of manufacture, a hollow cupl shaped valve having a spiral groove on its inner periphery, ex-

tending from the open end -of said valve vto its rear vvall. i

l 8. In a fluid actuated hammer, -a hollow cup shaped valve having an imperforate end and side walls, andinto which the pis,- ton is adapted to travel, and provided on its inner periphery with a groove for permitting passage of live motive fluid to initiallyl move the iston, said valve controlling admission o -exhaust of motive fluid to and from theopposite ends` of the cylinder, and being moved in one direction by live motive fluid and in the opposite direction by the momentum of the piston.

9. As a new art-icle'vof manufacture, a.

40 differential eup\shaped valve having 'an imperfor'ate end and impcrforate side walls and provided on its inner facewith a groove extending from the open end in proximity to said imperforate end. and having on its 43 outer periphery a plurality of grooves.

10. As a new article of manufacture, a differential hollow valve havingan imper-` forate end and imperforate sidel walls and provided on its inner face with a spiral U0 groove terminating in proximity to t-he imperforate end and said valve having on its outer periphery aplurality of grooves.

, 11. As anew article of manufacture, a

differential hollow valve, having imperforate walls, one end thereof being open and -the other end thereof being closed by an imperforate wall having its oute'r'surface beveled, the inner periphery of said 'valve being provided with a groove extending Go'from the open end into proximity to the closed end and the lesser diameter of said valve having on its outer periphery a plurality of annular grooves.

12. As an improved article of manufacturle, a hollow cup-shaped valve having one end closed by a thickenedv wall 11 and provided with heads 12, 13 and 14, and grooves 15 and 16, the inner periphery of said valve having the spiralgroove-17 therein.

13. In a fluid actuated hamm'ei, tie com-'i710 and having atits'rear Aend an imperforate 80 l wall, a. piston adapted to enter into said valve and t-he latterhaving means on its inner periphery for permitting passage of live'motive fluid to the rearof said valve to cause the initial forward movement of saidpiston, when the lat-ter is in its extreme rearward position.

14. .lira pneumatic tool, a cylinder, a piston, and a cup-shaped valve controlling admission of fluid to both ends of said piston, said'cylinder having a portf'or the fluid control of said valve opening into the cyline Y 'der at a greater distance from either end of the cylinder than the length of the piston, said valve having means ou its .inner periphery for. 'permiltingthe inlet :of live motive fluid to its rear to cause. the .initialforwar'd movement of the piston. v

15. In a pneuniatic tool, av cylinder, a piston therein, a cuplshapedvalve controlling admission of fluid to both ends of said cylinder and means for moving said cup-shaped valve operated through a port in the cylinder fart-her from either end of said cylinder than the length of the piston, said valve having means on its inner periphery for permitting the inlet of live motive. fluid to its rear to cause the initial forward movement of the piston.

16. A pneumatic tool comprising a cylin- 1,10 der, a cup-shaped valve located wholly at one end of said cylinder and controlling fluid admission to both ends of said cylinder,

' the latter having a pdrt for fluid' control of movement of said valj've and a hammering 115 piston in said cylindercompl'etely passing Said port in each direction of its travel, said valve having meanson itsinner 'periphery for permitting the inlet of live Amotive fluid to its rear to cause the' initial forward move- 120 ment of the piston.

17. A pneumatic ,t'oll ,comprising a cylinf; der, a hammering Ipi'ston therein having a 'stroke in excess of 'its length, and a cupshaped valve for admitting fluid to, both ends of said cylinder` and itself controlled by fluid from the cylinder through -a single port therein, and said piston passing beyond and uncovering said port when' in reach of its extreme positions, said valve having means coacting With said valve admission and exhaust of I sasso on its inner periphery for permitting the inlet of live motive fluid to its rear to cause the initial forward movement of the piston.

18. In a pneumatic tool, a cylinder, a hammering piston Whose largest diameter and major portion comprises one unbroken surface, and a cup-shaped valve located Wholly beyond one end of said cylinder exterior thereto for controlling the inlet of the motive fluid to opposite ends of the piston chamber to reciprocate the piston, said valve having means on its inner periphery for permitting the inlet of live motive fluid to its rear tocause the initial forward movementof the piston.

19. In a pneumatic tool, a cylinder, apiston therein, a valve block for said cylinder and a cup-shapedimperforate valve controlling admission of Huid to both ends of said piston, said cylinder having a port for the control of admission and exhaust of motive fluid to the rear of said valve opening into said cylinder at a greater distance from either end of the cylinder than the length of the piston, said valve being provided on its outer periphery with the exhaust groove 15 and the inlet groove 16 and said cylinder and valve block having' ports and passages, and piston for the motive fluid.

20. In a pneumatic tool, a cylinder, a piston therein, a valve block for said cylinder and a cup-shaped imperforate valve controlling admission of luld to both ends of said piston, said cylinder having a port for the control of admission and exhaust of motive fluid to the rear of said valve opening into said cylinder at a greater distance from either end of the cylinder than thedength of the piston, said valve having its closed end Weighted and being provided on its outer periphery with the exhaust groove 15 and the inlet groove 16 and said cylinder and valve block having ports and passages, coactin'g with said valve and piston for the admission and exhaust of motive fluid.

21. In an impact tool, a cylinder, a reciprocating piston the-rein, an imperforate cupshaped valve arranged in alinement with said piston and moving in the same direction as vthe latter, said piston being adapted to enter said valve, means for shifting said valve forwardly by live air pressure and means for enabling'said valve to be shifted rearwardly by the momentum of said piston.

SAMUEL OLDHAH.

Witnesses: E. HAYWARD FAIRBANKS,

H. S. FAIRBANKS. 

